The invention relates to couplings in general, and more particularly to improvements in couplings which can be utilized to separably and fluidtightly connect an end portion of a first tubular component (such as a nipple at one end of a metallic or plastic pipe) with one end portion of a second tubular component (particularly with one end portion of a flexible elastic hose). Still more particularly, the invention relates to couplings of the type wherein a sleeve-like tubular coupling member is insertable into the end portion of the second component and has flexible coupling elements engageable with retainer means at the exterior of the end portion of the first component.
Commonly owned U.S. Pat. No. 4,775,173 to Sauer discloses a hose coupling wherein a cylindrical portion of the tubular coupling member is insertable into the end portions of the first and second tubular components and its median portion is provided with external coupling elements having pallets which can engage a radial flank provided on an external retaining rib of the end portion of the first tubular component. The coupling elements extend radially outwardly of the cylindrical portion and their pallets extend substantially axially and radially of the cylindrical portion in order to be capable of pivoting into engagement with the flank of the retaining rib when the cylindrical portion is properly inserted into the end portions of both tubular components. A clamping ring is provided to surround the end portion of the second component and to urge such end portion into sealing engagement with the inserted cylindrical portion of the coupling member. When the coupling is fully assembled, the coupling elements extend radially of the tubular components well beyond the retaining rib of the end portion of the first component. This contributes to the bulk of the coupling, and the pallets of the coupling elements are likely to be accidentally detached from the retaining rib. Moreover, when one of the coupledtogether components is pulled in a direction to move its end portion away from the end portion of the other component, the junctions between the coupling elements and the cylindrical portion of the coupling member are subjected to the action of torque which tends to disengage the pallets from the radial flank of the retaining rib. Still further, the coupling element of the patented coupling is expensive because it must be made in a specially designed plastic processing machine. In addition, the entire coupling member must be made of one and the same material. This contributes to the cost of the coupling because the cylindrical portion need not be elastic and, therefore, such cylindrical portion could be made of a less expensive ductile or rigid plastic material.